Directional signal switch



w. l.. MAPPES ET AL ,2,781,429

DIRECTIONAL SIGNAL SWITCH Feb. 12, 1957 5 Sheets-Sheet 1 Filed Feb. 8, 1954 INVENTORS WILLIAM L. MAPPES AND GEORGE D. HART ATTORNEY Feb. 12, 1957 w. l.. MAPPES r A1. 2,781,429

DIRECTIONAL SIGNAL SWITCH Filed Feb. 8, 1954 3 Sheets-Sheet 2 (ST5 l INVENTORS WILLIAM LMAPPES AND GEORGE D HART ATTORNEY FIG.5

Feb. l2, 1957 Filed Feb. 8, 1954 922 95 FIG.9

w. I MAPPI-:s I=:r AL 2,781,429

DIRECTIONAL SIGNAL SWITCH 3 Sheets-Sheet 5 9 50 FIG. Io

INVENTORS WILLIAM I .MAPPI-:s AND GEORGE D. HART ATTORNEY United States Patent i DIRECTIONAL SIGNAL SWITCH William L. Mappes, Cincinnati, and George D. Hart,

Norwood, Ohio, assignors to Northeast Capital Corporation, New York, N. Y., a corporation of New York Application February 8, 1954, Serial No. 408,918

8 Claims. (Cl. 20G-61.37)

This invention consists in new and useful improve ments in directional signal switches for use in turn-indieating signalling systems for motor vehicles and relates more particularly to automatically self-cancelling switches for directional signals of this type.

In many conventional signal switches wherein the cancelling mechanism is located within the switch housing, a cam or linger is attached to the hub of the `steering wheel and so connected as to operate the cancelling mechanism. With this type of switch the cam must be very accurately located on the steering Wheel hub and is fastened thereto by means of -screws or pins which require drilling into the hub when the unit is assembled. Experience has shown that it is extremely difcult in the assembly of these mechanisms, to maintain the necessary accuracy due to the usually awkward position under the steering wheel of a vehicle and the cams are often improperly located during installation. Furthermore, in such installations, the cam often times must be bent to accommodate the various shapes of lsteering wheel hubs, peculiar to the different makes and models of Vehicles, in order to permit the use of one cam for many different applications, instead of having to supply different cams to accommodate each different shape which would naturally be an uneconomical method. Naturally, these cams must be of a relatively soft material to permit their bending and adaptation at installation and it necessarily follows that such cams will eventually bend out of position after repeated cycles of cancelling the switch and must be reset to their original positions.

One of the primary objections of this type of cancelling mechanism lies in the fact that the switch will cancel only when the cam has proceeded in its arc of travel until it has passed a given fixed point, and will never cancel with -a given arc of cam travel from diierent degrees of steering wheel turning. That is, if the cam has just passed the cancelling mechanism when the vehicle has completely entered its turn, the switch will cancel almost immediately after the driver starts to turn the steering wheel back to the straight ahead or neutral position, while at the other extreme, if the cam is immediately at the cancelling mechanism when the wheel is started toward its neutral position, the wheel must make over a complete revolution, since some additional travel is required for the cancelling operation.

These objections have been recognized and various types of switches have been developed in an effort to overcome the objections to the cam operated type of self-cancelling turn-switch constructions. Some of these efforts have involved a wheel made of material which has a high co-eiiicient of friction, and arranged to perform the cancelling operation by means of rotation due to frictional engagement with the steering wheel hub. Most of the switches of this type are constructed in such a manner that the friction wheel must be engaged at all times with the steering wheel hub, as a result of which excessive wear is produced on the friction wheel and periodic resetting of the switch in relation to the steer- -2,781,429 rammed Feb. 12, 1957 ICC ing wheel, is required. Also, since no predetermined relative position of the friction wheel and the steering wheel is obtainable, a frictional engagement is necessary between the friction wheel and the cancelling mechanism, thus providing another point of Wear in the train of friction which in many cases cannot be compensated for.

While some switches now available, are equipped with a retractable friction wheel, permitting its disengagement with the steering wheel hub, and some have methods of compensating for the Wear between the friction wheel or its pinion and the cancelling mechanism, all lswitches of the friction wheel type with which we are familiar, have the further disadvantage of cancelling almost immediately after the steering wheel is turned toward its neutral position or in the direction opposite that in which the turn is intended to be made. Since normal safety dictates and most States require that a signal indicating the intention to turn, must be given continuously during the approach to a turn, normal steering of the vehicle with the high steering ratio of the modern vehicle, will cancel the signal long before the intersection is reached. This is especially true if the road being travelled has a curve which must be negotiated during this last approach to the turn.

lt is therefore an object of this invention to provide a turn signal switch of the retractable friction wheel type which is adapted to cancel with approximately the same arc of wheel travel toward neutral, regardless of the position of the steering wheel when the travel toward neutral is started, thus overcoming the difliculties encountered in the operation and installation of the cam operated type.

A further object of the invention is to provide a simple and inexpensive method of permitting the friction wheel to disengage from the steering wheel hub when not in oper-ation, thereby eliminating unnecessary friction and wear at this point, and also to provide a means to permit the friction train to be self adjusting so as to compensate for any wear occurring in this train.

Another object of the invention is to provide a dwell or lag in the cancelling operation, which must be overcome before the switch returns to neutral position, thereby offering assurance that the vehicle has proceeded far enough into its turn to no longer require a signal. This also permits normal operation and steering of the vehicle in the approach to the turn, enabling the operator of the vehicle to completely disregard the turn-signal switch after it has been set in its turn-indicating position, without necessitating the holding of the switch on or looking to see if it is still in operation during the final approach to the turn, when his full attention to the road and his both hands on the steering wheel are required.

A still further object of the invention and a decided advantage in this friction-wheel type cancelling mechanism, is that the friction train in the switch can yslide or slip if the vehicle operator inadvertently or intentionally holds the switch in its operating position while negotiating a turn and returning to neutral, without dangerously jamming or locking the steering wheel, or noticeably increasing the power required to steer the vehicle.

With the above and other objects in View which will appear as the description proceeds, our invention consists in the novel features herein set forth, illustrated in the accompanying drawings and more particularly pointed out in the appended claims.

Referring to the drawings, in which numerals of like character designate similar parts throughout the several views,

Figure l is a vertical sectional view through our improved switch mechanism.

Figure 2 is a sectional detail of the friction wheel,

showing its supporting track and taken on line Z-Z of Figure'l.

Figure 3 is an enlarged detail illustrating one type -of spring tension means for use in connection with the friction wheel.

Figure 4 is arplan view ofthe switch mechanism with the upper housing cover removed to illustrate internal details, the steering `wheel and post being illustrated Iin section.

Figure 5 illustrates a wiring diagram typical for this type of device.

Figure 6 is a vertical sectional view taken substantially in the offset pla-ne of yline 6-6 of Figure 4, and

Figures 7 to ll, inclusive, illustrate diagrammatically, the sequence of operation of the cancelling segment.

iReferining first to 'Figure l, it will be seen that the assembly is enclosed in a two-piece 'housing gene-rally indicated by the .numeral and consisting of a lower or base member 21 and a cover 23.. The forward wall of the base member 21 is extended upwardly as at 23 and meets the corresponding forward wall of the cover 22, a transverse slot 24 for receiving the operating handle, being formed jointly in the adjacent edges of the housing sections. The side and rear portions of the base 21 are cut out to accommodate the corresponding, depending side walls 25 and rear wall 26 of the cover 22, as will be seen from Figures l and 6, the adjacent edges of the cover secti-ons being cut to complementary shapes to form a complete housing when assembled.

In order to gain access to the internal parts of the assembly as will later appear, the side and rear walls of thel base member 2l of the housing, are cut sufficiently low to avoid interference with the mounting screws etc., when the switch mechanism is installed. The cover 22 may be secured in place on the base 21 by means of one or more screws 2.7 (Fig. 6) preferably disposed in recesses 28 to avoid projection, and adapted to engage threads in thickcned. portions 29 adjacent the lower edge of. the cover 22.

The entire switch mechanism is mounted on the s eer ing column 30 of a motor vehicle, by means of a bracket 3i provided with a pair of linear parallel slots 32. shown in dotted lines in Figure l and through which screws 33 project into threaded holes in the base member 2 of the housing. Tie bracket 3i is secured to the steering column by means of an encircling metal band 34, the ends of which are turned in through slots 35 as best seen in Figure 4, the inturned ends being drawn together when the screw and nut arrangement 37 of the clamp 35 is tightened.

In mounting the switch assembly on the vehicle, the unit is positioned in any convenient radial location `on the steering column 3u and can be selectively adjusted ver tically on the column by sliding the bracket 3F. and its band 34 before tightening the .screw 37. Radial adjustof lthe unit with respect to the steering column 3Q, may be effected by sliding the switch forwardly or rearwardly on the bracket 31 and locking the same in position by means of the screw and slot arrangement 15E- 33. Thus, the switch can be positioned in such a manner that the frictionally operated cancelling wheel to be rcferred to hereinafter, is brought into contact with the underside of the steering wheel hub 3d', only when the cancelling wheel is in its position assumed when the switch is in its operating or on position.

The circuit selection unit generally .indicated by the numeral, 3S, is assembled on an insulating support 39, secured to the lower member 21 of the housing by any .suitable means, and .having mounted thereon four contact points 4d. A .second movable insulator 41 is spaced above the insulating support .39 and carries a spring contactor 4t2 which is .interposed between the insulators 39 and il and adapted to selectively engage contact points 4t) upon the rotary movement of the insulator 41. The movable insulator 41 is driven by a carrier member 43 by means of -three equally spaced, offset legs 44, adapted to engage complementary notches i5 spaced in the periphvery of `the insulator 41, as will be seen in Figure 1.

The carrier 43 is secured to an upstanding post 46 which extends through a bearing aperture 47 in the circular housing 48 which covers the circuit selection unit 3S. As will later appear, the inner end 9' of thc operating handle Sli is reduced to engage a complementary opening .in the post 46, so that upon the operation of the handle 50, the post 46, the carrier @connected thereto, and the movable insulator 41, with the spring contacter 42, are rshifted to selected positions.

Referring to the diagrammatic view in -Figure 5 which represents a typical wiring diagram for this type of device, and hearing in mind thc circuit selection unit just described, it may be seen that by positioning the handle tc either side of its neutral position in `the center, the spring contactor d2 fis brought .into contact with two of the contact points fili, closing the circuit from the conventional battery 5l, through the ignition switch 52, fuse 53, dashing unit 5d, to the signalling lamps 55, mounted normally on the four extreme corners of the vehicle and focused tothe front and to the rear. Thus, the signal lamps are intermittently energized on `one side only of the vehicle, giving a signal accepted by the motorists and authorities of the various jurisdictions as a warning of the intention to turn in the direction indicated by the position of the lamps on the vehicle.

Also included in the circuit is a pilot lamp S6, operated by the flashing unit 54 only when two lamps 55 are in operation, thus indicating to the vehicle operator that the system is functioning properly. As will be seen in Figures l and 6, the pilot lamp '55 is so positioned in the housing 2i), .that its light escapes the housing cover 22 through an aperture 57 which may be covered by any .suitable transparent lens 58. The aperture 57 is preferably located in the vcover 22, positioned .in such a manner as to be best visible to the operator between the spokes of the steering wheel.

The cancelling mechanism per se, consists of a frictionally operated cancelling wheel 6ft which is fabricated from a material with a relatively high co-efcient of fric` tion, such as rubber, and is provided on its upper side with an upstanding, integral hub portion 6l of the same material. This wheel is rotatably mounted on the upper 6?. of an angular supporting frame 63, the vertical leg of which is supponted at .its lower end `in a socket 64 located in the base member 21 of the housing 20. As seen in Figure l of the drawings', the lower end of the supporting frame 63 is provided with an oversize hole 65', adapted to receive a screw 66 which passes through the socket 64, thus permitting the supporting frame 63 to pivot freely in `the socket.

The cancelling wheel 60 is provided `with a bushing 67 .to minimize the friction between the bore of the canceiling Wheel and its axle 68, permitting free rotation of the wheel on the axle. The axle 68 extends thro-ugh a `slot 62 inthe upper leg 6?. and is .rigidly secured to a plate 69 which is slidably mounted in a pair of oppose-:l tracks 70 formed on the under side of the upper leg 62 of the supporting frame 53, as will be seen in Figure 2, and is urged 4in a direction generally away from the steering wheel hub 3d by means of a spring 71. One form of spring to accomplish this purpose is shown in detail in Figure 3, the spring being interposed between connecting legs 72 and 73 fixed to the plate 69 and the upper leg 62 of the supporting frame respectively, and normally tending to draw the plate toward the forward end of the legv62.

The bushing 67 -is preferably of such length that it projects beyond the limits of the cancelling wheel ait each of its ends, to provide low friction thrust bearings at these points, 4against a fiat washer 74 on `the under side of the wheel and a `split ring 75 adjacent the extremity of the wheel hub 61.

The forward end of the upper frame .leg 62 is turned downwardly at an angle as at '76 and at the intermediate portion of the lower edge lof this downturned member there is provided a V-shaped notch 77 which is best illustrated in the series of figures numbered 7 to 1l inclusive.

This notch 77 is so positioned as to norm-ally embrace the operating lever 50 when the latter is in neutral position and to minimize friction in operation, the lever 5 0 is preferably provided with a roller sleeve 78 at its point of contact with the notch 77, for the purpose hereinafter described.

As before stated, the angular frame 63 is fulcrurned at its lower end in the socket 64 and thereby capable of pivotal movement toward and away from the rear wall 26 of the cover 22. As shown in Figure l, the frame 63 isunder a normal forward tension by means of a coil spring 79 secured at one end to the supporting frame 63 and its other end to a guide frame 80. This guide frame 80 is horizontally disposed and overlies the circuit selection unit 38 as best seen in Figures 1 and 6. The longitudinal extremities of the guide frame 88 are slotted as at 81 and 82 to receive the vertical leg of the supporting frame 63 and the forward depending portion 76, respectively. Thus, lateral movement of the supporting frame 63 is prevented by the guide slots 81 and 32 while limited fore and aft movement is permitted.

The guide frame 80 is provided with a bearing aperture 83, adapted to receive the upper end of the post 46 of the circuit selection unit 38 and is `supported by four legs 84, the lower ends 8S of which are out-turned and drilled to receive screws 86, by means of which the frame 80 is secured to the base 21 `of the housing 29, as shown in Figure 6. This guide frame is centrally located over the circular housing 48 by means o-f the :close fit between the inner edges of the legs 84- yof the frame `and the outer periphery of the switch housing 48.

Overlying the upper angular legs 62 of the supporting frame 63 and pivotally secured to said leg, is a cancelling lever or segment generally indicated by the numeral 37 which coacts with the frictional cancelling wheel 60 in the manner hereinafter described. As best seen in Figure l, the cancelling segment 87 is pivotally mounted on the forward end of the upper arm 62 by means of a pivot pin 88. The upper portion of the segment is substantially step-shaped in cross section to accommodate the friction cancelling wheel 60, the upper end 'of said segment terminating in an upstanding shoulder 89 whose outer face is curved in an uninterrupted radius, the center of which is coincident with the axial projection of the point of rotation S8. rl`he curved face of the shoulder 89 in maintained in engagement with the periphery of the hub portion 61 of the cancelling wheel 60, by means of the spring 71 which operates upon the sliding plate 69 with a constant tension.

The forward end of the cancelling segment 87 is provided with a downturned portion 90 which overhangs the angular member 76 of the upper frame leg 62 and terminates in a notched edge 91. The shape of the notch 92 in the edge 91 will best be seen from the series of gures numbered 7 to ll inclusive, which diagrammatically illusltrate the relative positions of the frame notch 77 and the cancelling segment notch 92, as the device progresses through a cycle of operations. Here it will be seen that lthe notch 92 in the cancelling segment is relatively wide at its mouth 93 and terminates in a restricted upper portion 94 of a size to give only suiiicient clearance over the size of the operating handle Si), to prevent binding. The opposite edges of the notch 92 on either side of the restricted portion 94 are offset to provide inclined shoulders or ramps 95 which cooperate with the operating handle 50 in the manner to be described, it being understood that the length of the depending portion 9G is such that its notch 92 will straddle the operating handle 50 at all times.

Having described the construction and assembly of my improved cancelling switch, its operation is `as follows: The relative neutral positions of the operating handle S0, the cancelling segment 87 `and the angular projection 76 on the upper leg 62 of the supporting frame 63, are illustrated in full lines in Figures 4 and 6 and diagrammatically in Figure 7. When the operating handle is positioned to indicate a turn as `at a in dotted lines in Figures 4 and 6, the roller sleeve 78 carried by the handle 50 exerts a pressure against one side of the V-shaped notch 77 in the angular portion 76 of the frame leg 62. The frame 63, being interposed in slots 81-82 of the guide frame 89, is restricted in its transverse movement and the resultant force of the inclined edge of the slot 77 cams the entire supporting frame 63 upwardly on its fulcrum 64, against the tension of spring 79. This pivotal movement continues until the yoperating handle 50 has negotiated a sucient arc to slide under the edge 76a oli the 'angular member 7 6 as shown in Figure 8.

During this movement, the supporting frame 63 carries with it the cancelling wheel 60, projecting the latter through slot 26 in the casing and urging its periphery in compressed relation against the under side of the steering hub 30', as shown in dotted lines in Figure l. In this operation the handle 50 bears against the side of the restricted portion 94 01"'. the notch 92 in the cancelling segment 87, pivoting the latter on the pin 88, into the position shown in dotted lines in Fig. 6 and diagrammatically in Fig. 8. The cancelling segment 87, being carried by the supporting frame 63, thus rises away from the handle 50 due to the `action of the inclined edge of the V-shaped slot 77, until the handle 50 is positioned in the wider lower portion 93 of the notch 92.

During this movement of the operating handle 50, the circuit selection unit 38 is set into operation. The turning of the handle 56 rotates the post 46 connected thereto and through legs 44 and rotatable insulator 41, the contact spring 42 is rotated to close the selected circuit by engagement with two of the contacts 40, thus energizing the lamps on one side of the vehicle.

With the switch in its operating position, any rotation of the steering wheel 30 causes a rotation in the opposite direction, to be imparted to the cancelling wheel 60, and in like manner, the hub 61 of the cancelling wheel 60 imparts rotary motion to the cancelling segment 87, due to the frictional contact of this friction gear train 61-89 However, with the operating handle 5G now in the wider portion 93 of the notch 92, as shown in Figure 9, slight reverse movement of the cancelling segment 87 will not sta-rt the cancelling operation until the gap between the edge of the slot 92 and the operating handle has been closed, permitting normal steering of the vehicle without el'ect to the switch. As the vehicle enters the turn, the movement of the friction gear train continues until the side of the notch 92 strikes the :corresponding side of thc operating handle, thereby increasing the size of the gap. At this point of movement the cancelling segment 87 clannot rotate further and as a result, slippage occurs at the point of least f-rictional resistance in the friction gear train.

At the instant the steering wheel is rotated in the opposite direction, after the turn has been completed, the cancelling segment 87 rotates toward its neutral or central position as indicated in Figure l0. However, the switch unit 38 and its spring contact 42 are still in contact- 'ing position until the gap between the operating handle 50 and the opposite side of the notch 92 has been closed and the operating handle has been urged toward its neutral position su'iciently to remove the legs of the spring contactor 42 from the surface of the contact points 49. This consequent lag or dwell prior to cancellation of the signal, permits virtually complete negotiation of any curve or turn of a vehicle while the ysignal is still in operation, thereby greatly increasing the safety of such turn. Figure ll shows the relative positions of these parts as the operating handle is being shifted back to its neutral position.

It is well known in the art that any switch or electrical operating device where making and breaking of contacts is required, that at the point where the area between the contacts is small, any interruption of movement of the contacts or a slow movement thereof, will greatly increase the burning of contacts in the switch itself. Therefore, the notch 77 in the end of the support frame arm 62, is designed to be of such size and shape that the points of intersection between the sides of this V-shaped slot or notch and the straight end portions 76a, are positioned well to the outside of the center of the roller 7S on the handle 50, before the contact area between the spring contacter 42 and the contacts dil become dangerously small. It will be apparent that when the handle is urged toward the neutral position by action of the cancelling segment 87, the reaction of the spring 79 through the inclined edge of the notch 7'7, will quickly neutralize the handle, irn mediately opening the circuit to the signal lamps and thereby preventing any lag on a dangerously reduced contact area. When the handle returns to neutral the shoulder 95 in slot 92 simultaneously neutralizes the cancelling segment 87, and the cancelling wheel 6) is retracted from its contact with `the steering wheel hub 30.

Obviously, any wear on the hub 61 of the cancelling wheel will be taken up by the spring 71, and any Wear on the periphery of the wheel 60 can be compensated for by the adjustment of the switch unit on the bracket 31, or by repositioning `the bracket closer to the steering wheel on column 30. Also, the wear on the periphery of the cancelling wheel 60 is reduced, since it is not in constant contact with the steering wheel hub.

Since there is no positive mechanical linkage between the steering wheel 30 and the operating handle 59, a slip in the friction gear train will prevent locking or jamming of the steering wheel, should the handle be inadvertently held in the on or operating position, even while negotiating a turn.

From the foregoing it is believed that the construction and operation of our invention may be readily understood by those skilled in the art without further description, it being borne in mind that numerous changes may be made in the details disclosed without departing from the spirit of the invention as set forth in the following claims.

We claim:

l. A vehicle direction signal device comprising a base member, means mounting said base member on the steen ing post of a vehicle, a switch mounted on said base member, a horizontally ishiftable handle for operating said switch into open and closed positions, an upright support fulcrumed on said base and rockable toward and away from said steering post, a friction gear system including a friction wheel rotatably mounted on said support and movable therewith into and out of operative en* gagement with a rotatable portion of the vehicle steering mechanism, cam means on said support, engageable by said handle for rocking the `support and effecting said operative engagement, upon shifting of said handle from neutral position, a lever member pivotally mounted intermediate its ends on said support, means at one end of said lever friclionally connected with said wheel and adapted to be driven thereby to rotate the lever member in a direction counter to the direction of rotation of said Wheel, and means at the opposite end of said lever member en- -gageable with said handle upon rotation of said lever member to control the position of said handle, whereby rotation of said steering mechanism is transmitted to said lever and handle, through said friction gear system.

2. A vehicle direction signal device comprising a base member, means mounting said base member on the steering post of a vehicle, a switch mounted on said base member, a horizontally shiftable handle for operating said switch into open and closed positions, an upright support fulcrumed on said base and rockable toward and away 'rom Said steering post, a friction gear system including a friction wheel rotatably mounted on said support and movable therewith into and out of operative engagement with a rotatable portion of the vehicle steering mechanism, a pair of opp'ositely disposed cam surfaces on said support, respectively engageable by said handle for rocking the support and effecting said operative engagement, upon shifting of said handle in either direction from neutral position, a lever member pivotally mounted intermediate its ends on said support, means at one end of said lever frictionally connected with said Wheel, and adapted to be driven thereby to rotate said lever member in a direction counter to the direction of rotation of said wheel, notch means at the opposite end of said lever member normally overlying said cam means and engageable with said handle upon rotation of said lever member -in either direction, to control the position of said handle, whereby rotation of said steering mechanism is transmitted to said lever and handle through said friction gear system.

3. Mechanism as claimed in claim 2, including a guide frame on said base member, for directing the movement of said upright support.

4. Mechanism as claimed in claim 2, wherein said notch means is provided with a narrow portion adapted to preset said lever in cancelling position when the switch is manually set in operative position, and a wide portion to provide a gap between the side of the notch and said handle, said gap affording a lag in the cancelling operation by permitting travel of the lever prior to any travel of the switch unit to permit normal steering of the vehicle without cancellation of the turn signal.

5. A vehicle direction signal device comprising a base member, means mounting said base member on the steering post of the vehicle, a switch mounted on said base member, a horizontally shiftable handle for operating said switch into open and closed position, an upright support fulcrumed on said base and rockable toward and away from said steering post, a friction gear system including a friction wheel rotatably mounted on said support and movable therewith into and out of operative engagement with a rotatable portion of the vehicle steering mechanism, a pair of oppositely disposed cam surfaces on said support, respectively engageable by said handle for rocking the support and elfecting said operative engagement upon shifting of said handle in either direction from neutral position, a friction gear segment pivotally mounted intermediate its ends on said support, an arcuate shoulder at one end of said segment frictionally connected with said wheel and adapted to be driven thereby to rotate said segment in a direction counter to the direction of rotation of said wheel, notch means at the opposite end of said segment normally overlying said cam means and engageable with said handle upon rotation of said seg ment in either direction, to control the position of said handle, whereby rotation of said steering mechanism is transmitted `to said segment and handle through said friction gear system.

6. A vehicle direction signal device comprising a base member, means mounting said base member on the steering post of the vehicle, a switch lmounted on said base member, a horizontally shiftable handle for operating said switch into open and closed position, an upright support fulcrumed on said base member and rockable toward and away from said steering post, a friction gear system including a friction wheel rotatably mounted on said support and movable therewith into and out of operative engagement with a rotatable portion of the vehicle steering mchanism, a cam member Xed with respect to said support and engageable by said handle for rocking said support and effecting said operative engagement upon shifting of said handle in either direction from neutral position, a Imovable cam member pivotally mounted on said support and overlying said xed cam member` said movable cam member being frictioinally connected with said wheel and adapted to be driven thereby to rotate in a direction counter to the direction of rotation of said wheel, the cam portion of said movable cam member being engageable with said handle upon rotation of the movable cam member in either direction, to control the position of said handle, whereby rotation `of said steering mechanism is transmitted to said handle.

7. A vehicle direction signal device as claimed in claim 6, wherein said movable cam member overlies a portion of said wheel, an arcuate drive shoulder at one e-nd of said member, an extended hub on said wheel frictionally engaging said shoulder to drive said member and spring means urging said hub and shoulder into operative engagement, the cam portion of said member being located at the end opposite said shoulder and straddling said handle.

8. In a turn signal for motor vehicles including a switch unit, an automatically neutralizing switch control mechanism, comprising a friction wheel, a movable support mounting said wheel adjacent a rotatable portion of a vehicle steering mechanism, a switch operating handle, means controlled by the position of said handle for shifting said support and friction wheel to bring the latter into operative frictional engagement with said rotatable portion of the steering mechanism, an uninterrupted friction segment gear pivotally mounted on said support and frictionally connectedat one end to said wheel, its opposite end being engageable with said handle upon rotation of the wheel Iin either direction to return the handle and switch to neutral position, the said support being pivotally mounted at one end and shiftable by said handle to effect operative engagement of said friction wheel with the said rotatable portion of the steering mechanism, spring means normally urging said support and wheel out of engagement with said steering mechanism when the switch is in its neutral position, and cam means on said support, operating in conjunction with said handle, for effecting engagement and disengagement of the friction wheel with the steering mechanism.

References Cited in the tile of this patent UNITED STATES PATENTS 2,207,114 Bruderick July 9, 1940 2,308,108 Roedding Jan. 12, 1943 2,611,047 Barcus Sept. 16, 1952 

